Projeto otimizado de loops para a mitigação do campo magnético gerado por linhas e redes subterrâneas

Abstract

The growing demand for electricity in urban centers has been causing an increase in underground distribution and transmission lines and, hence, sources of low frequency electromagnetic fields. This has motivated discussions about the problems caused by the exposure of the population to these fields, making stricter the rules and laws that establish field limit values. Therefore, for some situations, it is necessary to use shields to mitigate the magnetic field generated by underground lines. That said, the objectives of this study were to analyze the mitigation technique based on passive loops and to implement an optimization algorithm to determine the best configuration for the loops. To this end, we developed methodologies for the calculation of the magnetic field in the presence and absence of the shield (magnetic problem) and the maximum permissible current in the transmission line (thermal problem). Thus, the factors considered in the optimization of the loop configuration were the efficacy of shielding, the decrease in the transmission line ampacity and the financial cost of the material. However, the goals stipulated in the design of loops are conflicting, requiring the use of multi-objective optimization techniques for the determination of the results. In the end, we present the solutions sets obtained by optimization for the shielding of the conventional stretch and the junction zone an underground transmission line